The production or recycling of nuclear fuel leads to the production of co-products, waste or effluents. It should be verified that the radioactive material content of these co-products, waste or effluents is acceptable in light of the regulatory thresholds.
For example, uranium oxide (UxOy), and in particular uranium dioxide (UO2), is used as nuclear fuel. Uranium oxide is for example obtained by converting uranium hexafluoride (UF6) into uranium oxide. The conversion is for example done first by countercurrent circulation of uranium hexafluoride powder and water (H2O). Such a manufacturing method is described in FR 2,771,752.
This conversion generates hydrochloric acid (HF) as an exploitable co-product. It should be verified that the uranium concentration in the hydrochloric acid does not exceed the regulatory thresholds defined by the nuclear safety authority.
To that end, it is possible to take regular samples and have them analyzed by a laboratory, for example using mass spectrometry, a molecular absorption spectrophotometer, etc.
Nevertheless, such analyses require the use, by qualified personnel, of improved laboratory devices that are expensive to purchase, maintain and operate. They require a length of time that may vary from several tens of minutes to a day depending on the necessary preparations and the type of measurement done. They are done at regular, but separated time intervals. These analyses are poorly suited to monitoring a continuous industrial process and in that case require intermediate storage and processing by lots of certain steps of the industrial method.